Conventional medical instrument are frequently used in practice as gripping, securing, and/or cutting tools. Thus, the jaw members can have blades for severing tissue or blunt surfaces for holding severed tissue, for instance, or stanching blood vessels.
In order to make the most flexible possible use of a medical instrument of this kind, on the one hand, and, on the other, to facilitate cleaning of the instrument, the known practice is to connect the tool detachably with the activation rod. The known connections between tool and activation rod, however, had the disadvantage that, as is known from EP 0577423 B1, they are of very expensive construction as screw-in or nesting connections, and thus simple, rapid, and thus cost-efficient tool replacement is not possible with these known instruments.
A conventional medical instrument is known from U.S. Pat. No. 5,496,347. In this known instrument, the activation rod is secured directly on the jaw members of the tool. For this purpose, the distal end of the activation rod has recesses into which cams configured on the jaw members engage. In order to secure the connection of the activation rod with the jaw members in the radial direction of the shaft, on the one hand the activation rod is mounted between the two jaw members and on the other hand the distal end of the shaft is configured so that the activation rod and the jaw members in this coupling area are surrounded by a housing, which is arranged inside the hollow shaft and in addition serves as a guide for the activation rod.
This known construction allows the tool to be secured on the activation rod without screwing connections; however, the complexity of installation—especially because of the use of the additional housing and the connection of the activation rod with the individual jaw members of the tool—is so great that, here too, simple, rapid, and thus cost-effective tool replacement is not possible with this instrument. Consequently it is the aim of the invention to design a medical instrument of the aforementioned type in such a way that the tool can be secured, especially as a one-way tool, simply and rapidly on the activation rod.